Some of most beautiful parts of England are “not necessarily” well protected
from development under controversial new planning rules, Nick Boles has
admitted.

The new National Planning Policy Framework, which came into force this week and requires planners to be in favour of "sustainable development" when making decisions about new developments, includes protections for Sites of Special Scientific Interest.

However, Mr Boles, the Planning minister, told MPs that in fact they might not be fully protected after all and suggested that new homes could be built in them.

SSSIs are the country’s very best and geological sites, including some of the country’s most spectacular and beautiful habitats. There are more than 4,100 in England, managed by Natural England, covering around 8 per cent of the country’s land area.

The NPPF states that "proposed development on land within or outside a Site of Special Scientific Interest likely to have an adverse effect on a Site of Special Scientific Interest (either individually or in combination with other developments) should not normally be permitted.

"Where an adverse effect on the site’s notified special interest features is likely, an exception should only be madem where the benefits of the development, at this site, clearly outweigh both the impacts that it is likely to have on the features of the site."

In the Commons a Tory MP demanded to know why Natural England had designated a former Ministry of Defence site in Kent as a SSSI effectively blocking a 5,000-strong housing scheme.

Mark Reckless MP said Natural England’s decision this month had the effect of “thwarting” the development and not considering “the economic impacts”.

The reason was because of a study by Natural England had found the development could be home to 84 nightingales. He said: “The comparison to be drawn is between those 84 nightingales and homes for 12,000 people and jobs for a further 5,000 people.

“We are told by the Prime Minister that we are in a global race, but it is not clear that the message has yet filtered through to bodies such as Natural England.”

Local councillors in Medway were frustrated by the decision, he said, urging Mr Boles to step in, ahead of a final decision by Natural England in July.

He said: “It is not surprising that council leaders in the area say that we need to end the absurd situation of a non-elected Government agency dictating to national an local Government on how to run things.

“Medway is an example of a council that is pro-development, that wants to support the minister and that wants to show that it is open for business.

“Will the minister assure me that our local council will be able to decide where is best for development to go, not ministers or their inspectors and still less these quangos?”

In reply, Mr Boles said that the SSSI qualification did not mean it could not be built on and he would be happy to speak to the chairman of Natural England to ask if the protection “can be managed to ensure that the houses needed” are built.

Mr Boles said that he could “well understand the dismay of Medway council, which is seeking to do what all Honourable members understand is necessary – to make provisions to build more houses”.

He said he wanted to reassure Mr Reckless “of two things”, adding: “First notification of a site as an SSSI does not necessarily mean that it cannot be developed but it does mean that the developer must make advanced efforts to mitigate, or, if they cannot do that entirely, to compensate for any impact on the site.

“Only last week I met the chairman of Natural England and I would be happy to explore with him the status of such a notification, how it came about and whether it can be managed to ensure that the houses needed for people in my honourable friend’s constituency are built.”

The comments appear to go against the spirit of the NPPF. Asked if the rules meant that SSSIs were protected from development, a spokesman for the Communities and Local Government said: “Yes.”

Neil Sinden, campaigns director of the Campaign to Protect Rural England said Mr Boles comments demonstrated the weakness of protections for SSSIs under the NPPF.

He said: “This case demonstrates how weak many of the provisions in the NPPF to protect valuable areas of landscape and wildlife sites from damaging development.

“The beauty of the English countryside and the wildlife it sustains should be at the heart of the Government's approach to sustainable development, not sidelined by a reckless drive for economic growth at any cost.

“Natural England is the Government's statutory advisor on the natural environment. It does not exist to rubber stamp environmentally damaging development. The clue is in the name.”

Labour’s shadow planning minister Roberta Blackman-Woods added: “We think that the Government are not keeping enough protections in place so that it is appropriate development rather than any old development.

“It is all about balancing the beauty of an area against development and we think the Government is in danger of getting to an imbalance.”

In September 2011, after the draft plans were unveiled, Prime Minister David Cameron stated the planning reforms would not affect protections for SSSIs.

The Prime Minister told MPs: “We are not changing the rules for green belt, for areas of outstanding natural beauty, for sites of special scientific interest.”

A Communities and Local Government spokesman said: "The strong protections for Sites of Special Scientific Interest are unchanged from the previous planning guidance published in 2005, known as PPG9.

"Under that previous guidance, and as the Minister stated, once an area is made a Site of Special Scientific Interest it is clear that if significant harm would result from a development then planning permission should be refused, but all development is not banned if there is adequate mitigation and clear community benefits.

"This was the case under the last Administration and it is the case now. Nothing has changed."

Sir Simon Jenkins, the chairman of the National Trust, has warned of a “war” between developers and local residents because of the loosening of planning rules.

Last week Mr Boles privately he had taken “a bit of flak” in the past few months, but “it will be nothing compared to the flak that I will have to take over the next few months. What I’m focused on is ensuring that more gets into the system – and consistently more.”

The Telegraph’s Hands Off Our Land campaign persuaded ministers to water down the scale of their initial plans, in the months leading up to the publication of the NPPF in March last year.